How many grams of acid are formed if 60g formic aldehyde reacts with silver oxide?

Given:
m (HCHO) = 60 g

To find:
m (acid) -?

Solution:
1) HCHO + Ag2O => HCOOH + 2Ag;
2) M (HCHO) = Mr (HCHO) = Ar (H) * N (H) + Ar (C) * N (C) + Ar (O) * N (O) = 1 * 2 + 12 * 1 + 16 * 1 = 30 g / mol;
3) n (HCHO) = m (HCHO) / M (HCHO) = 60/30 = 2 mol;
4) n (HCOOH) = n (HCHO) = 2 mol;
5) M (HCOOH) = Mr (HCOOH) = Ar (H) * N (H) + Ar (C) * N (C) + Ar (O) * N (O) = 1 * 2 + 12 * 1 + 16 * 2 = 46 g / mol;
6) m (HCOOH) = n (HCOOH) * M (HCOOH) = 2 * 46 = 92 g.

Answer: The mass of HCOOH is 92 g.